The Eco Egg Birdhouse is 100 % natural. It is made of Bamboo and is moisture resistant providing excellent insulation. The 1.5 inch hole is perfect for small birds such as wrens, bluebirds and chickadees. This egg shaped birdhouse features drainage holes, ventilation and inside steps to help fledglings step up and out when ready to leave the nest. It has a galvanized hanging cable and is easy to clean. Outstanding and unique, it will add a colorful and useful element to your garden or patio.